Input-Shaping for Feed-Forward Control of Cable-Driven Parallel Robots

TL;DR

This paper presents an input-shaping control method for cable-driven parallel robots that reduces oscillations and residual vibrations, validated through experiments showing significant improvements over unshaped control.

Contribution

It introduces a novel input-shaping approach combined with cable tension calculation to enhance vibration damping in CDPRs.

Findings

Achieves up to 72% reduction in velocity error amplitude.

Effectively attenuates residual vibrations during robot motion.

Validated through experimental tests on a prototype.

Abstract

This paper deals with the use of input-shaping filters in conjunction with a feed-forward control of Cable-Driven Parallel Robots (CDPRs), while integrating cable tension calculation to satisfy positive cable tensions along the prescribed trajectory of the moving-platform. This method aims to attenuate the oscillatory motions of the moving-platform. Thus, the input signal is modified to make it self-cancel residual vibrations. 5 The effectiveness, in terms of moving-platform oscillation attenuation, of the proposed closed-loop control method combined with shaping inputs is experimentally studied on a suspended and non-redundant CDPR prototype. This confirms residual vibration reduction improvement with respect to the unshaped control in terms of Peak-to-Peak amplitude of velocity error, which can achieve 72 % while using input-shaping filters.